...the fact you never even realized it _would be an assault_ even if you _were_ in his place tells everything we need to know the ra** culture around us.
It makes the VICTIMS thinks it's okay...
IT. IS. NOT. OKAY.
And it's nothing to do with age or teasing or anything.
If your partner doesn't give you consent for any reason, then you don't have consent. And no consent means you can't do sh**. It's really that simple.
(oc, "consent" not necessary means constant verbal validation, I mean, it's such a turn off when someone state every min what they'll do in the next min, like a doku commentary... Actions are consent too, so, of course you can make your first move like hug your partner (and ONLY parner, not random people..:XD), kiss them or something, and if reciprocates, it is consent. but that's the key here - reciprocate.
So if you want to make a move on your sleeping partner (pretending or not), you abolutely can - but you WAKE THEM UP FIRST!! And you do it WITHOUT A SEXUALLY MOTIVATED ACT. Which means you can't just undress them!! (and no suck them, fingering them, or whatever, oc), but you can caress them (not on genitals...), maybe kiss them on the cheeks, shoulder, or whatever is your everyday, regural NON-SEXUAL affection method.