for me as a survivor - doing some of the same things with my wife that were part of my abuse memories is one of the scariest things. it is not just the reminders of what happened back then - but also admitting that some of those things did really turn me on - as much as i hated it.
so now - when i am finally coming to terms with it all and can think about it objectively - i can recognize that there was nothing inherently bad about the acts - if done in the right setting, relationship, with mutual agreement, etc. example - being touched through underwear is a very big part of my history. it has been difficult for me to be comfortable with that in the past. now i find myself wanting my wife to do that - not as a way of re-enacting the abuse - but as a means of asserting - this is OK. i am over it. we are displacing an old bad tape with a new good one. my T calls it "re-wiring." it may be different for you 2 - but it's worth considering.
hope this helps a little.
"That you are here - that life exists, and identity; that the powerful play goes on and you may contribute a verse. . . What will your verse be?" Robin Williams as John Keating in "Dead Poets Society"