case fans: don't put your dick in these. stroke the outside carefully, in a circular motion, for maximum stimulation
usb ports: great place for penetration. flash drives are the traditional option but you can connect nearly anything, ask your partner if theyre into something specific. if theyre really kinky, try viruses or pentesting tools like the flipper zero.
power button: threatening to press it can be incredibly hot, but only actually press it with enthusiastic consent.
removable side panel: for getting really intimate. be very careful, the internals are sensitive!
hotswappable parts: sometimes SSDs (M.2 SSDs will be screwed in parallel to the motherboard, others may look different), HDDs (spinning disks inside big cases, usually get their own bay), and GPUs (big chips with fans attached) can be removed while your partner is running, but not all computers support this. this is a common part of BDSM, but make absolutely sure it's safe beforehand.
motherboard: the MOST sensitive part of their body! touch lightly and carefully. running the tips of your fingers along the traces is incredibly stimulating. play with the capacitors, too.
screws: loosening screws can be incredibly erotic, but be careful. especially with M.2 SSDs, this may cause problems! only loosen an M.2 drive if it is NOT mounted.
software: virus play was mentioned earlier, but also simply running very demanding software can be erotic.
download play: downloading embarrassing or illicit files is very hot. be sure to ask consent before installing league of legends.
firewall play: opening up or disabling your partner's firewall can be thought of as akin to exhibitionism. be careful with this, it can be a security risk, but most of the time it's not a big issue.
BIOS play: messing with your partner's BIOS settings can be incredibly intimate. remember, overclocking can be dangerous, only do it in small increments and very carefully! try starting with changing XMP profiles or something first.
that nub they have on thinkpad laptops: that's the clit.
remember some key safety tips:
ALWAYS wear protection! a static wrist strap is important if you are touching the internals, especially the motherboard.
heat warning! your partner will run hot when they're aroused. the GPU and CPU will burn you! even the SSD may run quite hot, especially during download play.
don't stick your dick in the fans. please.
for extra protection, keep viruses isolated inside a virtual machine.