Ursula lets Akko continue the worship, figuring it's probably for the best...

"I'm such a terrible teacher for allowing Akko to do something like that to me... a-although I can't deny it feels really nice, I kind of wish I knew that earlier... N-no! I mustn't think like that, I'm just doing this for Akko. She will notice it's not true, and won't have to do it again..." Ursula thought feeling conflicted about the situation as little moans were escaping her lips thanks to Akko's licking and massaging.

"Sensei, I think this is working! I think I'm feeling some energy in my body!" Akko said letting her sensei's pretty wiggling toes out of her mouth for a moment, not realizing she was blushing a bit herself now as well

"R-really? Hunyaaaa~ I-I'm glad to hear that Akko..." Ursula said trying to change her extremely relaxed position a bit but quickly coming back to it while letting out another moan as Akko quickly returned to the worship, this time putting her tongue, and licking lovingly inbetween Ursula's toes
"I-It's impossible... there's no way such a method would work... but then why would Akko feel her energy grow?" Thought the young teacher while her favorite student was having her way with her feet

Ursula was glad to have changed in her red tracksuit now... as Akko's warm wet tongue licked inbetween her toes, which undoubtedly were more sweaty than rest of her feet, but also more sensitive, she could feel warmth spreading all over her body and a very indecent sensation in her own panties, which could be visible for the enthusiastic witch if the blue-haired teacher wore her normal outfit.

"Hmmm... I'm sure that if we do it regularly I will be able to match others with my magic skills soon!" Akko said now moving her licking to the soles, where up until now her thumbs were just giving a normal massage.
"R-regularly?! I can't deny it feels good... but it's also so wrong, I am her teacher, I should lead her on like this just because it's pleasant to me..." Ursula thought feeling guilty, while her body kept getting warmer each moment

"Ahhh~ A-Akko... m-maybe you should stop already?"Ursula said uneasily between her moans, her face getting very noticeably redder by every moan, and her body feeling warmer with each loving lick against the sensitive and slightly sweaty skin on her feet

"A bit longer please Ursula-sensei! I must make sure that I get as much energy as I can! Besides you look like you are liking it too, right?" Akko said licking the pretty feet of her mentor, not fully realizing how exactly she was making her feel through her worship

"I-I can't bring myself to stop her when she looks so happy and determined... b-but if she doesn't stop soon, I might actually..."The bluenette thought, feeling as if there was probably a noticeable stain on her panties underneath her clothes by now, while her toes flexed and wiggled as Akko focused on her soles, tapping the younger witch's face.

"I never thought I would end up not minding to lick someone's feet! It must be the magic going to my body that makes it so good!" Though Akko, while diligently covering the heel of Ursula's foot with her saliva. Her teacher's lovely feet were starting to noticeably glisten with it in the soft lighting of the room, and Ursula's reactions were making it all the more fun and charming to her. The toes that tapped young witch's face seemed so adorable and playful to her... even if that probably wasn't the intention.

Meanwhile Ursula's moans only kept getting louder, and despite the feeling being so good, she knew she had to stop Akko before it went too far. On top of that her moans carried a risk of accidentally alerting someone nearby to come check up on her, which would almost certainly lead to her firing, and Akko's expulsion... on the other hand, could she really bring herself to stop her favourite student from enjoying herself like that? Especially if it felt good for her too... Maybe she could come up with some excuse before it was too late?