Jessica Simpson was seen entering John Mayer’s tour bus in Miami yesterday, and word has it that she’ll be along for the ride while he’s on tour. On Monday they worked out together at at their hotel gym in Miami, taking a yoga class and then lifting weights. Later that night they had a high profile dinner at Miami restaurant Nobu, showing that they’re ready to bring their relationship public.

Mayer will be performing in Jacksonville on the 25th, and Jessica seems to be going along for the ride. Just a few months ago, Jessica weathered a media backlash for her then publicist’s mistake of going public with the Mayer romance and then denying it. Now Jess is on board and on the bus.

Is it just me, or do you guys also suspect he could be using Jessica to get publicity for his tour? I don’t trust Mayer’s intentions at this point. After all, this is the guy who denied that he had something going on with Jessica last fall, and who bragged to a Rolling Stone journalist that he had lots of sex while on tour. Plaything Jessica is only going to serve his needs for so long.

Still, maybe Mayer isn’t as calculating as I think and it’s possible he’s giving it a geniune go with Jessica. On his blog he talks about his passion for performing amateur comedy, and says he’s touched when fans come up to him and tell them how his music has affected them personally. He comes off as thoughtful and geniunely interested in his music and hobbies.

Recently he wrote a cute post (permalink unavailable) offering The Smucker company a potential design for Jiff peanut butter single-use packets. He said he loves peanut butter and honey sandwiches but creates too many dirty knives making his favorite treat. His “P.B. Spredder” would have a little knife built into the package so bachelor pot-smoking PB-lovers like him would dirty less dishes when they’ve got the munchies.

I used to think he was a music gadget-loving geek who couldn’t possibly take goofy Jessica seriously, but I have a somewhat different impression of him now. Hopefully those cooking lessons Jessica has been taking will help her give Mayer some variety in his peanut butter-centric diet.

Here’s an excerpt from Extra! of them together out to dinner (Video removed from YouTube)

And here’s Jessica with John going to the tour bus. Jess looks really happy and she’s got JBF hair. Mayer looks annoyed. Thanks to SweetKisses for these pics.