Complex sentence: Studies have found that more boys and men have spontaneous nocturnal sexual experiences than girls and women, but female wet dreams may be more difficult to identify with certainty than male wet dreams because ejaculation is usually associated with male orgasm while vaginal lubrication may not indicate orgasm.
Split into simpler sentences: Studies have found that more boys and men have more frequent spontaneous nocturnal sexual experiences than girls and women. Female wet dreams may be more difficult to identify with certainty than male wet dreams because ejaculation is usually associated with male orgasm while vaginal lubrication may not indicate orgasm.