Is the 😘 emoji flirting?

Ok so i’m friends with an old teacher of mine. we talk here and there. He has a baby & a fiancé. I’m in a relationship. We are both adults and he isn’t a teacher before people go and say omg you’re a child it’s wrong lol.

I’m 23 hes like 35. He doesn’t live in town anymore but we make it a casual effort to keep in touch or meet up when we are in each other’s cities. No we do not talk every day or make it a HUGE deal to see each other. We bond over politics and things of that nature. He has sent me a kissy emoji before but I don’t think anything of it because I look at him as a close friend/near family member and like my uncles send me the emoji so idk. The most recent time he did it was when I wished him a happy bday. I said I love you happy bday! and he said love you too thank you with the emoji. It seemed innocent to me but then my guy friend was like uhhhhh when he saw the texts so idk. For the record my partner has seen our messages and doesn’t think anything of it which is why I was confused when my friend said he was flirting with me lol