TIFU by texting an old classmate and trynna hit on him as a joke

TLDR- TIFU by flirting with an ex classmate and prolly caused a fight between him and his gf

So it basically started with a call from my best friend where she decided that she wants to set me up with someone (my dating life is drier than the thar desert according to her). She decided on an ex classmate from our previous school and texted him through my insta while doin the talking stage for me.
That guy was prolly into me years ago but I had always dismissed him casually. However,he was surprised that I texted him after more than a year and was flirting with him. He considered it to be a joke and stated that he was in a relationship with someone while slightly flirting with me (in real,it was my best friend ofcourse). They were casually talking and messing around but my best friend didn’t believe that he has a gf and further tried to ship us together. The shit went down when her gf suddenly texted from his account that I should be in my limits and all,arguing with him as well. At the end, I took over the convo and congratulated her about her relationship, ending the convo on a neutral tone. However, the couple might had a fight because at the end he sent a text saying “thanks sweetie” and then edited it to just “thanks”.

I don’t know if I should apologise to the guy personally since his gf uses his insta and I texted sorry on behalf of my best friend.