Her body is hers. Sansa has trouble with this concept because it isn't known in Westeros. Certainly there are some husbands and wives that respect such a thing but Sansa has only been with one husband who respected it and she thinks that might have been a bit because she rejected him and she was so young and not for any high moral ground. She cannot put words in Tyrion's mouth.

This is different. She wants to be close to Rowan and he speaks of it not being a lack of want that keeps him away from her and she curls up close to him, sneaking her arm around his waist.

"I don't mind it when you touch me. Kissing was wonderful."