I've noticed when my boyfriend ejaculates that there isn't as much semen as there has been with other guys I've slept with. Not meaning to sound too gross here but it usually 'leaks out' with other guys afterwards but when I have sex with my boyfriend it doesn't do that. I noticed it the first time we slept together and every time since. This worries me abit as it makes me think that he will have problems having children. Is this normal?