Oral sex is a woman / man licking a woman’s vagina or a woman / man sucking a man’s penis (which is commonly know as a “blowjob” even though there isn’t any blowing involved!).
Some Sexually Transmitted Infections can be passed on through oral sex so always use a condom. You can get flavoured condoms and lubricants to make things a bit more fun, but some contain spermicidal which can irritate people with sensitive skin.
For oral sex with women, you can use a dental dam to place over the vagina and you can then give oral pleasure with the latex between the tongue and the vagina. This would be the same when performing oral sex anally. Or, use a condom for the same purpose – cut along one side so that you are left with a square shape. Do the same with the customised condom as you would with the dental dam and you can have safer fun.