Give him a "special" drink...

You go into your kitchen, telling him you´ll fetch him some water to go down with the sandwich. You fill a glass of water but you slip in a pair of sleeping pills. They should make him go out in a few minutes. As they dissolve you go back to the couch and give the glass to him. He eagerly downs the glass and then exclaims. "I´m going to sleep if that´s okay with you."

"That´s more than okay with me," you say. He looks confused, you reach over and stroke his crotch. "In fact, that´s my plan..."
He looks shocked and tries to get up, but sleepy as he is you pull him down easily. His struggle grows weaker while you stifle his cries for help with a firm pair of hands over his mouth.

His eyes close, and soon after you hear his breathing turn slow and deep. He´s fully asleep...