Why YSK: Vegetable based oil or oils that are not optimised for these specific purposes can fuck you over badly.
Regarding sun bathing, your skin will hate you, you will hate yourself and everything else. You will sizzle like a hot potato. Sun cream is your best friend, and as a former idiot who got sun poisoned recently "because the sun doesn't seem so bright", don't take that chance. Please be responsible regarding your sun exposure.
Regarding intercourse
Whether you do it by yourself or with other people, water based lubricant is the way to go. Why? It's crafted specifically for this purpose and it doesn't screw over your ph(like coconut oil would, for example).
And why should you care about ph balance? Because it messes up your health, putting you at risk for infections(which are painful if left untreated). There are people who think they are immune to diseases just because. It doesn't work like that. (Obligatory "pee after sex-or at least as soon as you can" mention to avoid UTIs, and for the love of everything that is around you, don't put sugar based things on (your) genitals, again, infection risk, it's needlessly sticky and not fun)
Also, use water based lube with condoms, as oil based lubricants will damage the condom and make it easier for it to break (silicone lube can damage some toys, so I personally recommend using water based lube with toys just to be safe).
I made this post because I heard people say that using olive oil for sun bathing is a good idea, and for the people who want to use baby oil or sunflower seed oil (I'm speechless at this point) to bone. It's not a good idea to do this. Using proper lubrication increases the pleasure levels for everyone involved.
Using sun screen is also very important, please use it. Have fun, be safe, read the labels. Might update with some relevant links in the following days.