I really wonder how this ended up happening. These 3 years were the time Vegeta was grinding the hardest, not only the gap between himself and Goku bigger than ever but he had to catch up to Trunks and the Androids as well.
I remember this filler scene (Or was it in the manga too?) with Vegeta pushing the gravity chamber so hard it blows up and Bulma saves him and takes care of him. She definitely threw himself on him as rebound from Yamcha, Vegeta wasn't chasing no ass besides Goku's.
Definitely fuck Bulma in the gravity chamber. Sounds like a free way to unlock SSJ2.
So that's what he was doing during the Cell-Boo timeskip.