You may choose to take this as a compliment. If he's turned on by you, yes, he might get an erection, but getting an erection isn't necessarily caused by being turned on. read more
An erection can actually be painful - some erections are harder than others. read more
Erections don't always mean sex. 3 years into a relationship, I'm surprised you don't know what he wants. You should try to be more open about your boundaries for having sex. There's nothing he can do about getting erect. read more