Someone sent me a DM on Twitter after I commented on a tweet of theirs. But I can't reply to their DM?

[Melondon684012]

I've been following them and their work on there for a while and commented for first time on a tweet of there's just praising their work. Instead of replying in the tweet thread I received a DM direct private message saying "Thanks". Do you think they are aware I can't reply. Or...
It just seems strange they would direct message me at all, or like a friend say just not say a general Thanks on the tweet thread.
Their an actor, and I'd be lying if I didn't find them attractive and would love to reply to their DM who wouldn't if your in this position. BUT I don't want to seem like a stalker and comment on many future tweets of theirs. I don't know I guess one small glimmer of hope inside me is wishing they think I can reply to their DM. It just seems strange to direct message when I won't be able to reply
Shucks

[Damien Gibson]

Maybe they blocked you

[Vid3ogamelova]

You can't message them unless they are following you. They messaged you because YOU are following them.