When I flirt (if we are at home in all these examples) , he responds, then I look him in the eyes with a sort of sexual smile on my face (he grabs my hand and leads me to the bedroom)
When he flirts and I respond with "the smile"
When he gets in bed and I scoot over to his side of the bed and hold him tightly (doesn't always lead to sex, for me holding is as great as sex, but it usually does)
When I'm in the room and he comes in and shuts and locks to door (daytime)
When I ask him "will you please snuggle with me"--he does and many times it leads to sex.
When I ask "for sex" (though it's unusual for me to be this direct so he knows I really need it)
When he grabs my hand(s) and places them on a certain part of his anatomy (it's never soft when this happens)
When he starts touching me in all my favorite ways.
When he asks for a specific "service"
PS I rarely say no; though I did on the day I attempted. It's pretty rare for him to be unresponsive as well.
Ocassionally, he drives me crazy but sex makes me smile. When we are having sex a lot, things seem more harmonious on a personal level between us.