EB3, EAD, have a permanent job, thinking of doing another contra

Hi. Everyone:

I want your opinion. I am a software engineer. I am EB3 and I am on EAD. I am in Middle West area and my permanent job pays a little over 100k. My wife also holds a permanent job. I am home based for current job.

Recently, I am contemplating to get another contractor job , also home based (corp. to corp., which means that I pay whole social security, 15%. comparing with the W2 based, the employer pays 7.5% and I pay 7.5%). Technically I am able to handle both jobs.

My question is: is it legal to do work on two jobs simultaneously? Also
what will happen if my current employer find out? Or if my current employer will ever find out (when at the end of the year the employer does my taxes, will the employer be able to see my other income)? If I keep a low profile: to take out my stuff from Linkedin, not to brag about my 'super' ability to handle the job requirement etc. I do concern if my current employer finds out my other employment. I am less concerned if my 'future' contractor employer find out. I would simply end my contracting job with them.

You opinion is highly appreciated.

Thanks.

Dan