Is it really normal for a guy who’s public about his relationship (posts stories with his girlfriend tagged) to be flirty in our conversations?

I’ve been talking with this guy on IG after we matched on tinder (I know) and he been really flirty and willing to meet me irl and then I start seeing him post tagged stories with this girl kissing and all.. I dont quite get it !
Is it really normal for a guy who’s public about his relationship (posts stories with his girlfriend tagged) to be flirty in our conversations?
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