As anal sex is considered a high risk sexual behavior for passing sexually transmissible infections (STI), you may want to use condoms during anal sex should you and your boyfriend ever decide to go from having a monogamous relationship to an open relationship.
Some couples value monogamy and commit to only have sex with each other. Other couples decide to have some degree of an open relationship, which may allow for one or both of them to have sex with other people.
On one hand, using a condom can help both people to feel more relaxed and confident about sex knowing that they are taking measures to greatly reduce the risk of pregnancy and some sexually transmissible infections, or STIs. On the other hand, using a condom changes sensation for men.
Though not having had intercourse by age 25 is less common these days, some people choose to wait to have sex until they find the right person, relationship or situation. There is nothing wrong with not having had vaginal intercourse by age 25.
Prostitutes who work at legal brothels are required to be regularly tested for infections. If they are found to have Chlamydia, gonorrhea or syphilis, then they have to stay out of work until they have been treated and tested again, and found to be negative for the infection on re-testing.
If a man recently ejaculated and then soon after, got aroused, it is theoretically possible that if any sperm were left over in his urethra from his last ejaculate, then the pre-ejaculatory fluids could pick the sperm up and carry them through the urethra.
One of the health-related problems with sharing sex toys is that it is not known how long certain bacteria or viruses can survive in sex toy materials. That means that sharing sex toys can result in sharing infections.
Some women who lubricate quite a lot enjoy it or look to it as a sign of their sexual excitement. Other women find that it may be enjoyable up to a point but that too much lubrication can interfere with vaginal sensation or their ability to “feel” their partner during intercourse.