Estorbar

Estorbar is one of those verbs that is usually handled in English via a preposition phrase: in the way. For this reason it's worth a little extra attention here. Here are some examples I've scribbled down:

• Con permiso, me estorbas. Could I get by (you)? You're standing in my way.
• Métete para que no estorbes. Get in your seat, you're blocking the aisle.
• Hay maestros que nada más estorban. Some teachers just take up space, get in the way of learning.
• A lo mejor te estorbamos para que tú hagas tus cosas. We might be distracting you from getting stuff done.
• Deja de estorbarnos. Stop getting in the way. We're trying to solve our problems without your help.
• Si llevo un paraguas después me va a estorbar. If I take an umbrella (to the bar), I won't have any place to put it. I'll have to carry it everywhere, what a pain.

As you can see, the blockage referred to needn't be physical. No estorbas could mean either you aren't physically in the way or it could mean your presence here is welcome, you're not a burden (as a houseguest, for example), depending on the context.

By extension, un estorboso would be someone who is in the way or who gets in the way. By the way, an unwanted person in the background of your photo is a colado, a word that also works for a party-crasher, an uninvited guest.