Even if this was pegging, there's nothing inherently BDSM around the act of pegging. It may be kinky, but it doesn't have to have a dom/sub or top/bottom dynamic. It can but it doesn't have to.
Source: am a cis man who has been pegged in a very romantic, loving, non-BDSM fashion.
You may call me a little anal (pun intended) about terms. I acknowledge that. IMHO getting kink terms right is really important for the community at large and how it is communicated with our partners and beyond.