Is there a way to stop pre ejaculation?

Unclear...: Do you mean premature ejaculation or the excretion before ejaculation? For premature ejaculation, it can be modified with understanding, behavioral modification, judicious use of topical numbing cream or oral use of drugs like SSRI. If concerning the so-called precum, nothing could be done since it is a part of natural process of male sexuality. More? Seek counseling... Best wish to health...