Why did my husband follow an old friend on IG?

My husband said he ran into an old friend from his childhood a couple weeks back. He said she was with her husband and they caught up for a bit and then she gave him her card and said they should get together sometime. I told him she probably wanted him but he said no and we laughed it off and didn’t speak of it again. Today I was on his IG page and saw that he found her and followed her. Should I be worried?
Why did my husband follow an old friend on IG?
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