Demi Lovato's romance with Mike Johnson has ''fizzled out''.

The 'Sorry Not Sorry' hitmaker enjoyed a string of dates with the 'Bachelorette' star last month, but it now seems the pair have decided to call time on their short lived romance, as sources say their relationship has ''run its course''.

An insider said: ''Demi and Mike's fling has fizzled out and they aren't seeing each other or texting like they were before. Nothing happened, it just ran its course.

''Demi was definitely interested in Mike at one point, but it was short-lived and she wasn't ever planning on dating him seriously.''

However, Mike hasn't given up hope when it comes to rekindling his romance with Demi, 27, in the future.

The source added to E! News: ''Mike hopes they can have a second chance again. But for now, he's fine with being friendly.''

Mike and Demi began dating in September, and the hunk admitted at the beginning of this month that she was a good kisser.

He said: ''We've gone on more than one date.

''I like her tattoos. We both have a lot of tattoos and she kisses really well ...''

And Mike liked the fact Demi was the ''aggressor'' who made the first move in their budding romance after first praising him online.

He said: ''For one, I'm all about her too and she definitely was the aggressor. I find it incredibly sexy. I love that.

''Like, you want me, come at me. If I want you, I'm going to come at you - and I'm coming at her as well.''

But the portfolio manager admitted he wasn't enjoying conducting a relationship in the public eye, though he knows it's much harder for the 'Sober' singer.

He said: ''To be honest, I personally don't like it. I am very private with my relationships, straight up.

''But she's in this light and that's why I said she's so humble and I think the world of her, because she has been able to have to deal with this crap.

''I can't even imagine from her perspective. I'm a gentleman. I'm not going to kiss and tell.''