In reply to Maitri@07:
This is exactly what I was saying in my last contribution. It generates interleaved seq_items, either starting with RD or WR. But they are not generated at the same time. If you want to have this you need 2 instances of the agent. Each of them is connected to 1 of the ports of your dual port device.
BTW you do not need in your example and what chris is proposing the fork/join_none. fork/join work perfectly.