It is not necessarily a turn off to girls if a guy has had a lot of experience with girls.
However, the guy shouldn’t make the mistake of constantly reminding her about it by either continuously flirting with other girls or talking to them while in the process of talking to her.
A good way to break free of the friend zone once and for all is to always make your romantic intentions be clear from the very start of your interaction with the person.
You should make that person aware of your romantic intentions to a good degree.
This is how you are able to quickly set the tone of what your interaction with this person will be like.