I wouldn’t bother
Slide shorts are primarily designed to provide padding around the hip and thighs for abrasion when sliding (hence the name) Many if not all current designs will have groin padding
If you’re going to be diving around then they are worth it, otherwise it’s another layer to get you hot & sweaty - especially as they are likely to be worn as an extra layer on top of your underwear and under your trousers
Baggy trousers perform the job without adding to what you wear, and easily absorb impact
Bear in mind that airsoft BBs are fired at maximums of either 1.3 or 2.5 joules, which compared to paintballs maximum of 12ft lbs / 16.3 joules
There is the added difference that paintballs are a larger frangible sphere vs airsofts small solid sphere which means the burst of a paintball disperses energy.
I have been shot a lot, I enjoy the adrenaline that comes with that (also a painkiller in itself)
BBs are a short sting, paintballs are more of a slap.
I’ve also taken more dick shots than I would like - in photography paintball designed baggy trousers do the job fine - a padded groin that is loose and baggy.
For CQB play I opt for a box in cricket shorts (they make me feel enclosed, but when you’re being shot at from a couple of feet away on the stairs they help!
Paintball tournament referees typically wear a towel hung from their trousers which deals with absorbing impact, I’ve considered that when photographing but don’t need it when trousers are baggy, and as a photographer I’m not in the middle of the field but on the boundary. (On practice / training days I would often go into the middle of the field for photo opportunities, and may be laid or squatting directly in line of shot, but still didn’t need that level of crotch protection)
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Protect your eyes, protect your fingers with gloves, your ankles with supporting boots.
For your body loose clothing does the job
Unless you are a diver & slider I would not bother with slide shorts, but perhaps look at paintball trousers that have some thicker padding at areas such as knees, thighs & crotch
** note that I write in English, therefore I say trousers, they generally get listed in American English as paintball pants
Avoid the tight skinny jean types of paintball trousers - they look stupid and don’t have the padding , also beware of “paintball training trousers / training pants” as they may be thinner and lighter without the padding
When you look up paintball trousers you will see scary higher prices (compare those shorts at £55 to trousers at £100 / £150)
Shop around, particularly for late season sales and last years range etc - or even better look up eBay and vinted
Another option is workwear trousers - check out your local DIY or trade counter and see what they have in heavy duty work trousers that provide multi layer / padded zones etc
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