The nude posing would probably be enough to cause Ianto's head to explode. The thing he wants the most is to be wanted.

Martha is incredible. Ianto has so much respect for her, but he also finds her very beautiful (and reminds him of his first love in many ways). He's sure she's way out of his league, however.

I think Ianto would be afraid of hurting Alice, so he'd be very careful about how he approached everything, dutiful and engaged.

Ianto, by the way, is immensely flattered by the attention. Thank you!