buddy up to somebody

Từ điển Oxford Advanced Learner 8th

ˌbuddy ˈup (to/with sb) derived
(NAmE)
1. (BrE ˌpal ˈup (with sb)) (informal)to become friendly with sb
•You and your neighbour might want to buddy up to make the trip more enjoyable.
2. to become friendly with sb in order to get an advantage for yourself
Main entry: ↑buddy_derived