Edie, Instead of asking for sex, how about asking for something less threatening--discussing sex, taking a bath together, cuddling, kissing, massage? I think if you increase the zone of comfort, then the sex will naturally ensue, or the obstacles will be revealed.
I agree that it's too early for an ultimatum.
If your H declined sex over the weekend, he owes you an explanation as to why, and an alternative to your invitation.
Do you have any ideas as to why he's being avoidant around this issue?
CL
CL 53 W 54 M 20 yrs. 03'-09' Separation + Old Patterns + GAL 10-14' Piecing
"The Master allows things to happen. She shapes events as they come."