Splitting and romance - being curious

[rolling_stone]

Well, I'm wondering about correlation between splitting and romance. My (currently not) gf, a possible pw BPD (never heard of a diagnose, but she reveals many BPD schemes), happens to cut off all the emotions regarding me from time to time, especially when we talk/argue about difficult for her things. Sometimes, she would try coming back to her previous bf, sometimes - involve in other romantic relations during those times.

Is it possible that a pw BPD has to act out (by, f.e., involving in romantic relationship) during splitting phase?