You describe a very low risk sexual exposure. Condom slippage on withdrawal probably is not a risk at all, and oral sex is very low risk, chapped lips or not. I do not recommend any STD or HIV testing after this sort of exposure. But if my reassurance doesn't ease your mind, be tested for gonorrhea, chlamydia, syphilis, and HIV in about 6 weeks.
Good luck-- HHH, MD
HHH, MD