Steven Tyler wants to marry Justin Bieber and Hailey Baldwin

Steven Tyler told TMZ that he is in the marriage biz ... and he's ready to officiate the proper nuptials for Justin Bieber and Hailey Baldwin.

The Aerosmith frontman was spotted on Tuesday at LAX and he flashed the online publication a card he got in the mail, making him an ordained minister who can now officiate weddings. He paid 80 bucks, according to TMZ.

See below the hilarious Halloween costume he tweeted of himself on Monday and caption, THIS #HALLOWEEN IM YOUR AUNT WHO LOVES A DOLLAR GENERAL DEAL AND MISSES A GOOD FILENE’S RUN EVERY DAY OF THE WEEK...SHOW ME YOUR COSTUMES!!! AUNTY HAS SPOKEN!!! BOO!

Steven's post: