However, during the course of the event, Wade and Yelene fell in love with each other. However, despite a kiss, the romance never truly flourished.
But, after the Thunderbolts believed Wade to have died, Yelena secretly sewed Wade's head back on his decapitated body and the healing factor did the rest, so some feelings were there.
In later stories, unrelated to Deadpool, it was revealed that the Black Widow Wade had feelings for was in fact Natasha Romanova in disguise, the original Black Widow, working for Nick Fury, turns out most of the T-Bolts felt the same way too, and Headsman, Ghost, and Paladin all turned against the other T-Bolts to save her and Songbird.
Unfortunately, Black Widow is killed by a Hydra influenced Captain America, punching her neck with his shard shield while she sacrificed her life saving the other Spider-Man/Miles Morales from him.
Wade and Black Widow met in the following comics: