You can't change the IP address that an OpenDNS server will return when your system looks up an IP address for a domain name, e.g, example.com. If the OpenDNS server returns an IP address for one of their own web servers, that web server can do an automatic redirect to another URL, e.g., from http://example.com to https://example.com, if the IP address points to example.com by returning an HTTP 301 status code to your browser along with the redirect URL. They could redirect your browser to https://example.com or http://someothersite.com as long as example.com resolves to an IP address for their own server.
You could however modify the hosts file on your system to point to the correct IP for example.com. On Microsoft Windows systems the file is found at
C:\Windows\System32\Drivers\etc\hosts. Edit the file with a text editor, such as Notepad, but be sure Notepad doesn't add a .txt to the end of the file name, and add the following line to the file, substituting the real IP address and fully qualified domain name (FQDN):
If you might use www.example.com or example.com, add both to the host file. E.g.:
Note: if your account isn't in the administrators group on the system, you will need to right-click on Notepad, or whatever editor you use, and choose "Run as administrator" and then provide the userid and password for an administrator account in order to save any modifications you make to the hosts file.
You can use some other DNS server, e.g., the one provided by Google at 184.108.40.206, to find the correct IP address for www.example.com by issuing the following command at a command prompt:
nslookup example.com 220.127.116.11
Or you could get the IP address for example.com by using an online DNS service, such as DNS Lookup.
Then whenever you put http://example.com in your browser's address bar, the system should first check the hosts file for any FQDN to IP address mapping. If it finds a relevant entry there, it does not need to consult a DNS server to obtain an IP address.
Since your system is configured to use the OpenDNS parental control DNS servers, e.g., see FamilyShield Router Configuration Instructions, rather than the regular OpenDNS DNS servers, you are being redirected to the block.opendns.com system. I.e., since your system is using 18.104.22.168 and 22.214.171.124, rather than 126.96.36.199 or 188.8.131.52, since the latter return 184.108.40.206 for sex.com as does Google's DNS server at 220.127.116.11 while the former returns 18.104.22.168 as the IP address for sex.com, you are sent to block.opendns.com rather than the web server for the site.
$ nslookup sex.com 22.214.171.124
$ nslookup sex.com 126.96.36.199
$ nslookup sex.com 188.8.131.52
If you connect to port 80 at 184.108.40.206 by telnet and emulate the query a browser would submit by entering the query below you can see the response from the website at that IP address:
GET / HTTP/1.1
The response is as follows:
$ telnet 220.127.116.11 80
Connected to 18.104.22.168.
Escape character is '^]'.
GET / HTTP/1.1
HTTP/1.1 403 Forbidden
Date: Sun, 09 Aug 2015 18:05:01 GMT
I'm uncertain now what you actually want to do. If you want to visit the actual website as your question suggests, the hosts entry should allow you to do so, if you add the following entries to it:
If, however, you wish to redirect your browser to go to a website you control as your comment suggests, then you will likely need to use a proxy server, such as Fiddler and add its security certificate to the trusted root certificates list on your system, so it can be a man-in-the-middle (MITM) so that the browsers on your system don't realize they aren't getting the actual security certificates for sites you visit using HTTPS. Some malware, such as Genius Box, uses MITM attacks to intercept and alter HTTPS traffic.