How to have safe sex with married girlfriend?

Q: I have sex with my married girlfriend two to three times a month. She also has sex with her husband. Initially we have unprotected sex but when I ejaculate I wear a condom. But a colourless liquid comes out of my penis during foreplay. My girlfriend is pregnant and she is confused as to whose baby it is. Please help, we are sextremely worried.

A: You are indulging in unsafe sex. The colourless liquid i.e. the precum fluid can have sperms. Either men could have caused the pregnancy.