We've done DP with a TIA a few times, and thinking of trying out both penis and (small) vibrator in pussy. Size wise should be ok I think. Has anyone done this? Any tips?
We do it occasionally. We've always found it easier if you insert your penis first and then slide the toy in slowly and gradually beside it. If you put the toy in first it can be really difficult to hang onto it while you push yourself in. Remember plenty of lube ......try to find a toy has a fairly large base....it's easier to keep hold of with slippery fingers xx
We do it sometimes with toys and with "the real things" with friends. Taking a toy and a cock or two cocks takes practice and patience, one usually slips out as the other goes in and with two men getting the legs right is usually amusing. Not something to be done hurriedly! 
Agree the advice above regarding toy use. It's good to practice with a toy and a cock several times before trying two of the latter, but two of the real thing is much preferable.
A small toy works perfectly or you can get a double penetration strap on that works a treat once you get the hang of the best angles etc. We found that it was easier for my partner to slide a dildo in First and then she would mount me cowgirl style for me to slip in and rest the suction base on my pubis. It’s tricky when your trying to get it right but it’s fun and exciting.
Have a look at the DP strap ons:
https://www.lovehoney.co.uk/sex-toys/strap-ons/double-penetration-strap-ons/
We do have a “feather” which you basically slide inside the vagina and it’s penis shaped, it stays in place while you penetrate and then you can slide it back out once your finished but I don’t believe they stock these anymore.
This something we've recently started doing and it's the best. Using a flexible dildo is useful as the angle can be a bit tricky sometimes. I find cowgirl is good then I can reach around and insert the dildo, or reverse cowgirl with the same approach.
Lots of lube and it should happen, my other half is quite petite but really enjoys a good stretch. We've got lots of thick toys (cock sleeves, dildos etc.) and I'm fairly girthy and I can tell you it feels incredible when there's a toy in there as well.
Weirdly she can take some pretty huge toys and DPP with me and some of them but we haven't managed vaginal fisting yet - a long standing fantasy for both of us.
Just goes to show you don't need to be a total size queen to achieve DPP!
did try this and went well
slimline vibrator went in second, above the penis and styed in place ok. practice will only make it better...
thanks for the tips
We have done this is the past ( one real one toy) and We have always found it so hard to get a good thrust going. You need a lot of lube to get them in , but then the lube slides them back out so isn't so great. We have now given up trying 🙄