In Hell, with his healing ability muted as it is, Natasha might still get the chance, if she really wants it.

Currently, Bucky will selfishly take all the freedom he is given, trailing lower still, until his long legs are folded over completely, and he's eye level with her crotch. He uses his metal arm, free of claws, and reaches it to slip between her thighs, seeking out her clit.

It's still a cautious move, one of curiosity and desire to please.