The next day, more chest workout

You meticulously wiped Mia's cleavage and neck clean with the tissues and used the spray bottle to sanitize the bench after you. Only then you became aware of the burly guy waiting next to the incline bench press. You had no idea how long he had stood there watching.

"Looks like you're finally done, good!", you heard him mutter.

"Um, sorry, do you want to tittyfuck her next?", you asked him.

"No, dude, why would I want to do that", he said, shaking his head. "I just want to use the damn incline bench"

"If you want to cum again tomorrow, I can give you some more tips", Mia said, zipping up her top again. "I really suggest you come to me specifically. I am the best qualified instructor for these kinds of chest exercises. Have a nice day!"

With that, Mia wandered off to assist some other gym-goers in a more traditional manner.

The next morning, you woke up with a boner. You decided to have a quick breakfast and then head to the gym first thing. You had no idea if Mia would be working already and what you would do if she wasn't there. Luckily, the first thing you saw when entering the gym was Mia chatting idly with the receptionist.

"John, so glad you came again! Are you ready for that chest workout we talked about, or do you want to do something else?", she said cheerfully.

"Chest workout, definitely!", you nodded eagerly to her.

"Great, let's get right to it! The gym is mostly empty, so I can show you some variations on yesterday's exercise!"

Mia walked you to the regular bench press. "This is the regular bench press", she explained as she sat on the bench and stripped topless. "You can use this when you can't or don't want to use the incline bench. This exercise is slightly different in that it will target more of your biceps and less of your pelvis. You'll need to sit on my stomach, in a slightly higher starting position than yesterday."

You took off your pants and underwear and sat on Mia's stomach, your cock erect over her chest.

"That's perfect. Now, can you guess what the next step is?", she quizzed you.

"Make... the cleavage?" you suggested.

"Very good, but aren't you forgetting something?", she asked as she handed you a bottle of baby oil. You took the bottle and poured a generous amount between Mia's tits. You rubbed the oil all over Mia's huge boobs, making them glisten invitingly, then rubbed the excess oil on your cock.

"Mmmh, that's good, better too much than too little. Now you can make the cleavage"

You grabbed Mia's huge oiled tits and sandwiched your shaft between them.

"Good. Now, you'll notice you can't move your hips as much in this position, so you'll need to do something different. Remember where the resistance controls are? Good! Grab there and push towards my head, maintaining resistance at a comfortable level"

You did as told and pushes Mia's tits up, stroking your cock once with her cleavage.

"Good! You can use the entire movement range of the breasts for maximum effect. Now, for the second part, you PULL", she said.

You pulled Mia's tits down towards you, making a single loud CLOP as they stopped against your lower stomach.

"That's perfect! Now try some reps. Remember steady pace and feel free to add pelvic movements if possible"

You started moving Mia's boobs around your cock and bucked you hips slightly. You spent a minute like this, Mia's enormous oily boobs giving a nice "CLOP CLOP CLOP"

"Great, stop right there", she said as she sat up and pushed you off of her. "Now, the next two exercises can be done without any equipment at all, but I recommend using a gym mat to protect your knees. She took a gym mat off the wall, placed it on the floor and knelt on it.

"This one is similar to the one we did yesterday on the incline bench, but you'll need to squat lower to get the starting position so it targets the legs more. Try it!"

You stood in front of Mia and squatted down to reach her boobs, grabbed them and started fucking her oiled cleavage. After another minute of this, Mia commanded you to stop again.

"That's perfect. You're a natural."

She then lay down on the gym mat.

"The next one is a bit hard on the knees, but it's a great variation if you want to target the woman's face or continue to missionary. For the starting position, you'll want to kneel on the floor, straddling my chest."

You got on your knees and without waiting for additional instruction, started tittyfucking Mia's huge rack with vigor.

"Good, good, I can see this one is already familiar to you"

You panted heavily as you rammed your erection in and out of Mia's tight cleavage.

"Hold it, hold it, I have one more thing to show you", Mia shouted, realizing you are close to blowing your load.

You got up from over her just in time.

"Now, the following exercise can be done without equipment just about anywhere, so why don't we go to the lounge to rest and hydrate and I'll show it to you there"

You nodded and followed her to the lounge. You grabbed a bottle of carbonated water from the fridge and sat down to drink it.

"Just tell me when you are ready to continue", Mia said, sipping from her own bottle.

"I'm ready. I'm not tired at all", you told her.

"Okay, just stay where you are", Mia said, producing a stopwatch. "You might think this isn't an exercise at all, because you don't have to work any muscles. But the muscles we'll be training is your pelvic floor muscles. You can't locate them by imagining you have to hold in your pee. This is done with the pelvic floor muscles. Try that now."

You did as she told, clenching your pelvic floor muscles as it you had to pee real bad.

"Find them? Good. Now, in the following exercise, you are going to try and delay your ejaculation by using these muscles for as long as you can. Got that?"

You nodded in accord.

Mia put a gym mat on the floor in front of your chair and knelt on it. She lined up her huge breasts with your cock, said "Time... starts... NOW!" and pressed the button on the stopwatch. Then she grabbed her tits and started giving you a tittyfuck.

You figured the best strategy would be to wait until you start feeling like you need to cum and then clench your pelvic floor muscles to delay the cumshot. Her tittyfucking felt amazing but not too good that you would start holding in yet.

After a while, Mia slid one of her hands into her cleavage and around your cock, stroking it with her hand and boobs together. This felt better but not enough so that you would be afraid of losing it. Mia amped up the resistance by popping your cock into her mouth and sucking it while giving you the hand and titty fuck. You started clenching as you knew you wouldn't last like this for long.

Mia picked up the stopwatch and placed her thumb on the button, looked you straight in the eye and said "That's great, but don't you really want to cum all over these huge ass titties. Cum on my fucking face! Let that fucking cum all over the place!"

You let out a grunt and you cock started sending splatters of cum on Mia's tits. She ticked off the stopwatch, shouted "TIME!" and then pointed your cock at her face to catch the rest of your cumshot on it.

"2:38. Looks like you're going to need to train more", she said, reading the time off the stopwatch.